Process for the extraction of resin from coal



Patented Aug. 26,- 1930 V I I umr'eo 154mm omen WILL! 1).

GREEILOF BAUER, UTAH, AssroNoR T COMBINED METALS REDUCTION communions'roox'rori, UTAH, A oonrormrron or UTAH PROCESS non 'rrm nxraaorrou ornnsm anon COAL R o Drawing. Application fled April 19,

' There are certain coals which contain a valuable resin. Heretofore, ithas been pro-- posed to extract the resin by means of solvents such asbenzol. This method is exensive and wasteful of the solvent used. It asalso been kproposed to separate the resin from the coal '3 use ofliquids with high specific gravities. he contamination of theproductsand mechanical losses of the liquid 1' used make a procedure ofthis kind expen-' slv'e.

This invention is based upon the discovery that the relative flotabilityof resin is enough greater than that of coal that the resin can beeffectively floated from coal by a suitable flotation agent such as oneof the higher alcohols, turpentine, cresol, or one of the pine oils, orthe like.

I have found that amyl alcohol is particularly advantageous as thefrothing agent for the separation of resin from coal, although otherrecognized frothing agents may be used. I find that amyl alcohol gives acleaner resin and a better recovery than the other fr'cthing agentsnamed. I

I have'also found that the resin froth conoentrate produced by using oneof these frothin agents contains appreciable quantities 0F finelydivided coal which lowers the grade of the resin, and if the resin isrefioated in the presence of a small amount of potassium alum mostofthis finely divided coal can be eliminated and a high grade resinobtained. The highly concentrated resin so obtained can now be,dissolved in suitable solven'ts for making varnish or lacquer or forother purposes and the resin solution further purified by centrifugalseparation, filtering or other means. 4e The invention involves treatinthe resincarrying coal, reduced to a flotab e size, i. e., of a sizesufficiently fine to liberatethe resin from the coal, and in the form ofa water pulp with a small quantity of am 1 alcoholor other frothingagent in a flotation machine 1829. Serial No. 856,623.

or a paratus, whereupon the resin collects in the orm of a froth and canbe removed in the usual manner. 4

. The coal remains in the pulp as the tailing andl can be recovered andused as powdered coa The resin froth which carries some very finelydivided coal can be mixed with a suitable quantity of water, a smallquantity of potassium alum added and the resin refloated in anotherflotation machine or apparatus thus making a clean resin, the finelydivided coal remaining in the pulp as tailing.

In carrying out the invention, it is preferable to use cold waterbecause amyl alcohol is a solvent for resin and its solvent action isfacilitated by heat, although thisis not a necessary limitation of theinvention.

The following example illustrates the practice of the invention:

500 grams of resin-bearing coal from Salina Canyon, Utah, was groundwith 2cparts of water to approximately pass a 40-mesh screen, which inthis case was sufliciently fine to liberate the resin from the coal. Anaddi tional quantity of water, sufficient to give a 1: 3 pulp, was addedand the pulp introduced into a froth flotation machine. Here amylalcohol was added in the proportion of 0,6 pound per ton ofresin-bearing coal and the whole agitated in the usual manner. A frothformed which carried the greater portion of the resin and was removed,the coal remaining in the pulp vas a tailing.

The resin froth was now prepared for and subjected to selectiveflotation treatment that is, the resin froth was introduced into aflotation machine, water added in sufficient quantity to fill themachine to workin level, 0.4 pound of potassium alum perton o originalresin-bearing coal was added, the whole agitated, then 0.2 pound of amylalcohol per ton of original resin-bearing coal was added, and a newclean resin froth was thus formed, which was removed in the usualmanner.

resin from resin-bearing coal, wh1ch com- The following table shows theresults. a four tests: v

Test 1 Test 2 name 'r wt. wt. wt.

Resin coal 100. o; 100. o 100. 100. e Resin 96% pure froth concentrate.7. 2 7. 0 7. 1 6. 9 Taillnz-Coa1 residue 92.8 as. o v 92.9 93.1

After the removal of the resin by froth flotation, vthe coal tailing orresidue can be, used directly as powdered coal fu p What I claim is:

1. The method of effecting separation of" resin from. resin-bearing:coahawhich com: :1 prises comminuting such coal and forming aux. 'pulpthereof, adding tosuch 'pulp a frothing agent that has a greater.afiinity for resin than forcoal and subjecting the same to frothflotation treatment such frothing 'agent-being" used inzqua-ntitysufficient to float most of the resin but insufficient to-float much ofthe coal.

2. The method of recovering-resin from resi-n bearing coal, whlchconsists in comminuting such coal and form ng a pulp thereof,

adding to such pulp a flotation agent of the class'which includes higheralcohol, turpentine, cresol and pine oil, in the proportion of aboutsix-tenths of a pound of such flotation agent to a ton of coal andsubjecting thepulp to froth flotation treatment.

3. The method of effecting separation of resin from resin-bearing coal,which co'mprises comminuting such coal and forming a pulp thereof,adding amyl alcohol to such pulp in the proportion of about six-tenthsof a pound of aniyl alcohol to a ton of coal and subjecting the same tofroth flotation treatment. I p 4 4. The method of effecting separationof prises comminuting such coal and forming a pulp thereof, addingafrothing agent to such pulp and subjecting the same to froth flotationtreatment'to form a resin froth, placing said froth in a flotationmachine, adding to the froth sufficient water to fill the flotationmachine to working level together with about four-tenths of a poundofpotassium alum per ton of originalf coal, agitating the same, and

then adding about two-tenths of a pound of amyl alcohol per ton of resinbearing coal and subjecting the mixture to froth'flotation.

5. The method of recovering resin from resin-bearing coal, whichconsistsin commiouting such coal and forming a pulp thereof,

adding to such pulp a flotation agent of the class which includes higheralcohol, turpentine, cresol and pine oil, in the proportion of aboutsix-tenths of a poundof such flotation agent to a ton of coal andsubjecting the pulp to froth flotation treatment to'form a resin froth,placing said froth in a flotation machine, adding to the frothsufficient water to v fill the flotation machine'to working leveltogather with about four-tenths of a pound of -potassium alum per ton oforiginal coal, agitating the same, and then adding about twotent hsof apound of amp} alcohol per ton of resin bearing coal and enjectingtheniixture to froth flotation.

6'.vThe method of effecting separation 'of resin from resin-bearingcoal, which com-.1

prises comminutin such coal and forming a pulp thereof, adding amylalcohol to such pulp in the proportion, of about six-tenths of a poundof aui'ylijalcohol to azton'of coal and subjecting the same to frothflotation treat-- merit to form a resin froth, placing said froth in aflotation machine,.iadd.ing to theafroth' suflic'ient water to filltheflotation machine to working level together with about four-tenths of apound of potassium alum per ton of original, coal, agitating the same,and then add ing about'two-tenths of a pound of Uhyftlcdsubject- I holper ton of resin-bearing coal and ing the mixture to froth flotation. I

7. The method of recovering resin from resin-bearing coal which consistsin formin such coal into a water pulp and subjecting the same toordinary froth flotation treatment to form a resin froth, forming'saidfroth into a pulpby adding water thereto together with potassium alum inthe proportion of about six-tenths of a pound thereof to a ton of theoriginal coal and agitatin the same, and then adding a fresh sup 1y 0frothin agent in the proportion of a out two hun r'edths of one percentthereof to a ton of the original 00:11 and forming a new resin froth.

8. The method of effecting separation' of resin from resin-bearing coalwhich com-' prises comminuting such coal and forming a pulp thereof,addin suitable flotation agents to such pulp and su jecting the same tofroth flotation treatment to form aresinfroth, re-

.ing a coal depressant and a frothing agent to the pulp and thenfloating the resin.

Signed at Stockton,'Utah, thisvl2th day of April, 1929.

WILLIAM D. GREEN.

